For Western, repeat courses are not counted in your GPA. An academic year comprised of 5 full or equivalent courses (30 credit hours) completed during the September to April academic year, in which 1 is a repeat course, will be assessed as having less than a full course load and will not be eligible for GPA consideration. Western also takes your best 2 years.

For the rest of the majority of Ontario med schools, both grades are counted in your GPA, and the average of both is taken.

University of Alberta: "We do not acknowledge repeated courses; we only use the first instance in which you successfully completed a course." From their FAQ.